Rohrer, a Mennonite (MC) family name, meaning "inhabitant of the swamp land," originating in the Swiss Emmental. Gertrud Rohrer and Margreth Rorer, both farmers' wives, are named as early as 1529 as Mennonites. Anna Rohrer, of Habstetten, arrested in 1567 but released after recanting, was apprehended again in 1571; she was tried on 27 November 1571, at Bern and gave interesting information concerning the congregational life of the Swiss Mennonites. Notwithstanding severe torture she refused to give the Bernese officials any information on other members of the church.

Among the Swiss Mennonites immigrating to the Netherlands in 1711 there was Barbara Rohrer (born 1671), of Bollingen, the wife of the Reformed Veits Sagimann. She died on the journey at Amsterdam. In the 1690's some Rohrers immigrated to Alsace and from there circa l732 to America.

The first Rohrer members to sail the Atlantic were Johannes and Johann Gottfried, who came 11 September 1732. Johannes married Elizabeth Snavely in 1735, settling in East Lampeter Township, Lancaster County, Pennsylvania. He had seven sons and a daughter, hence the name soon spread. A grandson Henry Rohrer (1784-1840) went to the Shenandoah Valley, Virginia; a second grandson, Isaac Rohrer (1787-1840), located near Canton, Ohio, and another, Abraham Rohrer, an ordained preacher (1788-1878), moved to Medina County, Ohio, where he became bishop. Among the ordained men in Lancaster Conference were Ephraim Rohrer (1811-91) of Manor, John Rohrer (1827-1908) of East Petersburg, and Israel D. Rohrer. Michael Rohrer (1816-93), a bishop at Canton, Ohio, 1865-93, and Samuel D. Rohrer (1879-1955), a preacher of Wadsworth, Ohio, are among the ordained Rohrers. Hinke mentions thirteen Rohrer immigrants, but Johannes is the only one known to the Mennonite church.